Oguchi disease is a rare autosomal recessive form of congenital stationary night blindness in which all other visual functions, including visual acuity, visual field, and color vision, are usually normal. A typical feature of the disease is a golden or gray-white discoloration of the fundus that disappears in the dark-adapted state and reappears shortly after the onset of light (Mizuo phenomenon). The course of dark adaptation of rod photoreceptors is extremely retarded, whereas that of cones appears to proceed normally (summary by Fuchs et al., 1995). For a general description and a discussion of genetic heterogeneity of Oguchi disease, see CSNBO1 (258100).

X-linked congenital retinoschisis (XLRS) is characterized by symmetric bilateral macular involvement with onset in the first decade of life, in some cases as early as age three months. Fundus examination shows areas of schisis (splitting of the nerve fiber layer of the retina) in the macula, sometimes giving the impression of a spoke wheel pattern. Schisis of the peripheral retina, predominantly inferotemporally, occurs in approximately 50% of individuals. Affected males typically have 20/60 to 20/120 vision. Visual acuity often deteriorates during the first and second decades of life but then remains relatively stable until the fifth or sixth decade.

Any Oguchi disease in which the cause of the disease is a mutation in the SAG gene.